We Seal & Rebuild Chimney Crowns & Stop Leaks Fast!

When we’re called about a leaky chimney, one of the very first things we do is get up on the roof and look at the chimney crown. That’s because, in our decades of experience, we’ve learned that the chimney crown is often to blame.

This cement covering that lays over the top of the chimney is what keeps rainwater, sleet, and snow from coming down into the chimney top. But when it doesn’t stop the water, there’s a problem.

Why Do Chimney Crowns Leak?

If your chimney crown is leaky, chances are it’s because of one of these things:

  1. The chimney crown has deteriorated or developed cracks.
  2. The chimney crown wasn’t constructed the right way when it was installed.

Let’s talk about each of these issues and how they become such a problem…

First off, there’s the possibility that the crown has deteriorated or developed cracks and is now letting water into the chimney. How does this happen? Well, it can happen as a result of this killer combo: moisture + temperature changes.

Moisture from rainwater, sleet, or snow gets absorbed bit by bit into the crown — possibly through hairline cracks or just because the material used to build the crown is naturally porous. But the trouble comes when temperature fluctuations are introduced.

Let’s say it’s in the mid-forties and it rains all day long. Then, that night the temperatures drop down below freezing. What’s happening to the water that was absorbed into the crown? It’s expanding (when it freezes) and contracting (when it thaws).

This process is known as the freeze/thaw process, and the movement that the moisture creates inside the crown can cause a lot of damage — including bigger cracks and fractures. Which means even more ways for water to get in and cause damage in the future.

Another cause of crown cracks and deterioration is age. The wear and tear that comes with storms and house settling over time can eventually cause small cracks to get bigger, and crowns to crumble and deteriorate.

And the final most common cause of leaky chimney crowns is bad construction. Specifications for proper crowns include a thickness of at least a few inches at their thinnest point, a drip edge that extends beyond the chimney chase, and a slightly downward angle on each side of the crown.

If built properly and well maintained, a chimney crown shouldn’t leak. But if it was poured too thin, built flat, or made without a drip edge, leaks are pretty much inevitable.

How Do You Fix A Leaky Chimney Crown?

Okay, enough about how this happened, let’s talk about how to fix it and prevent future problems…

Crown Repair Option #1 — Repair & Seal

If your chimney crown was built and installed correctly, but it has cracks and fractures, we’ll evaluate the extent of the damage before recommending a fix. It may be that we can simply repair the cracks, fractures, and deteriorating surfaces using one of our effective crown repair and sealing products and techniques, like CrownCoat or CrownSeal. In many cases, this simple fix can eliminate the leak and make a damaged crown like new.

And since the products we use protect against the freeze/thaw process and provide 10+ years of protection against leaks, you won’t have to worry about another leak springing up in just a few short months or years.

Crown Repair Option #2 — Rebuild

If the crown is severely damaged or wasn’t built right at the start, the best option may be to remove the crown and build a new one in its place. This can be done relatively quickly, and because we follow the NFPA 211 guidelines step by step and are trained chimney professionals, you can be confident the results will be quick, effective, and professional.

Ulster, Dutchess & Greene County, NY & The Surrounding Areas, You Need Leaky Crown Solutions That Last — Call True Ventilation

Don’t let that leaky crown wreck your attic, walls, or chimney. Call True Ventilation at 888-775-9498 for fast, professional results and leak solutions that work! We serve Orange, Suffolk, Dutchess, Columbia, Ulster, and Greene counties, and scheduling is easy!


Your leaky chimney repair may just be a matter of installing or sealing the flashing. Call us to schedule an inspection today.